How to redact personal info before pasting into an AI tool

Often the quickest way to get help from an AI chat tool is to paste in the real email, note or message you are working on. That is also how names, addresses and account details end up in a third party’s system. A short redaction routine fixes most of that.

Published 2026-10-03 · Prompt Desk

Why redact at all

When you paste text into an AI chat, it goes to a service run by someone else. What happens to it afterward depends on that service, your plan and your settings, and you usually cannot verify it from the outside. You also may have obligations to the people in the text, such as clients, students or guests, or rules from an employer or school. The simplest way to stay on the safe side is to not send identifying details in the first place. Most tasks do not need them: an AI can tighten a follow-up email just as well when the recipient is “Client A.”

What to look for

Go through the text with this list in mind:

• Names of people and businesses, including nicknames and first names alone.
• Contact details: email addresses, phone numbers, street addresses, links to profiles or private documents.
• Numbers that identify: account, order, case, student or employee IDs, card numbers, government ID numbers.
• Credentials: passwords, access codes, lockbox or door codes, API keys, one-time links.
• Indirect identifiers: a rare job title plus a small town, a specific date and place, a distinctive story. These can point to someone even with the name removed.
• Sensitive details such as health information, finances or legal matters, which usually should not go into a general chat tool at all.

A five-step routine

1. Decide what the task really needs

Ask what the AI has to know to help. For rewriting tone, it needs the message and the relationship (“a long-time client,” “a new vendor”), not who they are.

2. Replace with consistent placeholders

Use labels that keep the text readable: [CLIENT_A], [EMAIL_1], [PHONE_1], [PROPERTY]. Use the same label for the same thing each time, so that “Jordan” and “Jordan’s sister” still make sense as [PERSON_1] and [PERSON_1]’s sister. Keep a private note of what each label stands for.

3. Use a tool for the mechanical part

Emails, phone numbers and links follow patterns, so software can find them quickly. The free Placeholder Swap tool on this site replaces emails, phone numbers, links, card-like and SSN-like numbers, and any names you list with placeholders such as [EMAIL_1]. It runs in your browser tab, and the text you type is not sent anywhere. Type the names you want hidden into its names box, one per line, since it cannot guess them.

4. Read the result yourself

This step is not optional. Automated pattern matching is not a guarantee. It will not catch a name you did not list, a street address, a misspelled email, a detail like “the red house next to the church,” or deal and project information that should stay private. Read the output line by line, then search it once for the original names to confirm they are gone.

5. Put the real details back afterward

When the draft comes back, swap your placeholders for the real names and details in your own email or document. Then check that nothing was lost or changed. If a placeholder was reworded or dropped, fix it before sending.

A prompt line that helps

Tell the tool how to treat the placeholders so it does not try to fill them:

The text uses placeholders like [CLIENT_A] and [EMAIL_1] in
place of real details. Keep them exactly as written. Do not
guess what they stand for, and do not invent names, numbers
or addresses.

What redaction cannot do

Redacting reduces what you share. It does not make a tool suitable for regulated or highly sensitive material, and it does not change any rule your workplace or school sets about AI use. If you are not allowed to use an AI tool for a type of information, redaction does not change that. When in doubt, leave the detail out or check with whoever sets the policy.

Make it a habit

Build the routine into how you work: write your prompts with placeholders from the start, using fill-in-the-blank templates instead of pasting real messages. The free try pages work this way, with two blank-filling prompts per desk, and the Prompt Desk packs are built on the same idea. Whichever way you work, the principle is the same: give the tool the facts it needs, and keep the rest to yourself.